Carburetor



Patented Dec. 1932 UNITED STATES PATENT oFFica v LOUIS C. OSWALD, OF DAYTON, OHIO, ASSIGNOR TO DELCO-LI GHT COMPANY, OF DAYTON,

OHIO, A CORPORATION OF DELAWARE lowing description, reference being had to.

CARBURETOR The present invention relates to internal combustion engines and more particularly to fuel charge forming devices therefor.

One of the objects of the present invention is to provide improved means for supplying an internal combustion engine with a rich fuel mixture when the atmospheric temperature is cold and to vary the richness of the fuel mixture in accordance with atmospheric temperature variations. I

One manner of carrying out this idea is to provide an improved device responsive to atmospheric temperature for varying the level of fuel in a carburetor fuel chamber, which device is adapted to'maintain a relatively high level of fuel when the atmospheric temperature is low and to gradually vary the level of fuel as the atmospheric temperature gradually increasesto thus maintain a relatively low level of fuel when the atmospheric temperature is high.

Further objects and advantages of the present invention will be apparent from the folthe accompanying drawing, wherein a preferred form of the present invention is clearly shown. 7

In the drawing Fig. 1 is a diagrammatic illustration of an internal combustion engine and showing diae grammatically oneway of supplying fuel to the engine carburetor; Fig. 2 is a vertical view in cross-section of a carburetor forminga part of the present invention; and.

Fig. 3 is a fragmentary view of a portion of view of the movable overflow outlet and a portion of the actuating means therefor.

Referring to the drawing, the numeral 20' designates generally an internal combustion engine having a fuel intake 21. The intake 21 is in communication with a passage 28 formed by a carburetor 24' having one end thereof attached to the intake 21 by screws 25. A casting 27 forming a passage 28 and having an opening 29 to allow the passage of air from the outside through the passageways 28, 23 and through the intake 21 to the en variations.

Application filed January 29, 1930. Serial No. 424,317.

gine 20, is connected to the opposite end of the carburetor 24 by screws 31.

Anysuitable means may be employed for supplying fuel to a bowl or fuel chamber 40 of the carburetor'24. In the present instance I have provided, preferably, an engine driven fuel pump 41 connected with a fuel supply tank 42 by pipe 43. The fuel pump 41 is provided with an outlet pipe 45 which pipe is connected with the fuel chamber 40 of the carburetor 24 by a connection 48.

The carburetor 24 includes a fuel outlet passage formed by a fuel nozzle extending below the level of fuel in the fuel chamber 40 and leading to the passage 23, and through which the fuel may be supplied to the engine by the suction created by the movement of the pistons within the cylinders thereof. A throttle valve 5 5 including a butterfly 56 is adapted to control the passage 23 to thereby control the speed ofthe engine 20. Any suitable means may be employed for controlling the throttle valve 45, such as, an engine speed responsive governor (not shown).

In order to vary the richness of the fuel mixture being supplied to the engine 20, in response to atmospheric temperature variations, I have provided temperature responsive means 58 associated with a movable overflow outlet in the form of a collar 60 to thus vary the level of fuel in the chamber in response to said atmospheric temperature The temperature responsive means 58 includes a bimetallic thermostatic blade 62 secured on one end thereof to a lug s 64 of the chamber 40 by bolt 65f The opposite end of the blade 62 is adapted to carry a yoke-shaped member 67 operatively connected with the movable overflow outlet 60 by pins 69. The movable overflow outlet 60 is adapted to cooperate with a standpipe 72, preferably by a machined sliding fit, to thus provide an overflow passagefor the chamber 40. The standpipe 72 is connected to the fuel supply tank 42 by apipe 7 5 to return excesby the position of the movable overflow outlet 60.

- of a movable fuel overflow outlet In the event the levelof fuel should fall to the top of the standpipe 72 when the engine is inoperative due to leakage around the standpipe, upon starting of the engine the fuel pump will very quickly bring the fuel level to the top of the collar 60 because the fuel pump delivers more fuel than that which is consumed by the engine and that which can leak out of the chamber around the standpipe 72.

For the purpose of illustration I have shown a relatively high level of fuel indicated at 80 and a relatively low level of fuel which is indicated at 81. When the atmose pheric temperature is relatively cold, the temperature responsive means 58 will cause the movable overflow outlet 60 to assume the position shown in Fig. 2 to thus maintain a relatively high level of fuel. As the atmospheric temperaturegradually increases, the temperature responsive blade 62 will gradually bow downwardly, as viewed in the drawing, to thus gradually vary the level of fuel in the chamber 40. Thus a relatively low level of fuel will be maintained in relatively warm weather and a relatively high level of fuel maintained in relatively cold weather. Obviously, the change of the hydrostatic head pressure in the chamber 40 will cause a change of level in nozzle tube 50.

Thus the engine 20 will be supplied with a rich fuel mixture when the atmospheric temperature is cold and be supplied with a leaner mixture in warmer weather, which mixture, by the present arrangement, will become gradually leaner as the "atmospheric temperature gradually increases and gradually becomes richer as the atmospheric temperature gradually becomes colder.

While the form of embodiment of the "invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a carburetor, the combination with a fuel chamber having a fuel outlet assage, or said chamber, and bimetallic thermostatic means associated with said movable overflow outlet for varying the level of fuel in said chamber. I

2. In a carburetor, the combination with a fuel chamber having a fuel outlet passage, of a movable fuel overflow outlet for said chamber, and temperature responsive means asso ciated with said movable overflow outlet for varying the level of fuel in said chamber.

3. In a carburetor, the combination with a closed fuelchamber having a fuel inlet passage and a fuel outlet passage communicating therewith, of a fuel overflow outlet for maintaining a predetermined level of fuel in said chamber, and temperature responsive means associated with said overflow outlet for varying the level of fuel maintained thereby in said chamber.

4. In a carburetor, the combination with a fuel chamber having a fuel inlet passage and a fuel outlet passage, of a fuel overflow outlet for maintaining a predetermined level of fuel in said chamber, means associated with said overflow outlet and having an inlet opening communicating with the inlet of said overflow outlet, said means being movable relative to said overflow outlet for varying the level of fuel in said chamber, and temperature responsive means for actuating said first named means.

5. In a carburetor, the combination with afuel chamber having a fuel inlet passage and a fuel outlet passage, of a fuel overflow outlet for maintaining a predetermined level of fuel in said chamber, a collar surrounding the inlet end of said overflow outlet and movable relative thereto for varying the level of fuel in said chamber, and temperature responsive means for actuating said collar.

In testimony whereof I hereto aflix my signature.

LOUIS C. OSWALD. 

